DESCRIPTION (Adapted from the application) The overall goal of this core is to enhance the effectiveness of the CURE center program by continuing to provide CURE investigators who have independently-funded research projects with facilities, training and assistance for morphological, imaging and functional studies of transmitters, receptors, channels and other integral proteins in native and transfected cells. The core continues to offer services for visualizing cellular organizations and functions. These include an array of contemporary morphologic and imaging approaches that have a broad application in cell biology and neurobiology and will add new or improved imaging technologies to facilitate investigations in signal transduction that have developed during the past several years. The following services will be included: A. Fluorometry of isolated cell suspensions for determining changes in cell Ca2+, H+ or other ions accessible to fluorescent probe analysis; B. Immunohistochemistry for the localization of transmitters, hormones, receptors and transporters at the subcellular and cellular levels; C. Axonal tracing of neuronal pathways innervating the digestive system and controlling digestive functions; D. Assistance and training for light microscopy and photomicroscopy; E. Computer assisted image processing and analysis for quantitative determinations of changes in the expression of a given substance and for morphometric analysis of different cell populations; F. Confocal microscopy equipped with UV laser for the analysis of intracellular pathways involved in cellular signaling and cellular and subcellular localization of proteins; this system will also allow for a direct reconstruction of the relationship between identified nerve terminals and defined targets; G. Ion imaging of intracellular fluorescent probes for the analysis of signal transduction pathways in single cells. This entire system has been upgraded; H. Fluorescent imaging systems for in vitro measurement of intracellular cAMP levels using single excitation dual emission configuration in single cells. A microinjection system to introduce non-permeant dyes and non-permeant inhibitors or facilitators of signal transduction pathways into cells for the direct visualization of intracellular events is available in conjunction with the fluorescent imaging systems; I. Molecular modeling for a reasonable prediction of protein folding, either in the membrane or extramembrane domain of an integral membrane protein, which allows the prediction of accessible antigenic sites or to model the effects of mutations.